王徐庄油田歧646-2井沙一下碳酸盐岩储层特征研究

Reservoir Characteristics of Carbonate Rocks in Well Qi646-2 of Wangxuzhuang Oilfield

摘要: 本文讨论了王徐庄油田沙河街组沙一下亚段碳酸盐岩岩石学及储集物性特征。碳酸盐岩主要有介形虫灰岩、螺灰岩、砾屑灰岩、鲕粒灰岩、泥晶灰岩、泥晶白云岩；孔隙与裂缝是两种主要的碳酸盐岩储集空间类型，以孔隙–裂缝组合的形式出现。孔隙主要有原生粒内孔、原生粒间孔、遮蔽孔、窗格孔、铸模孔等溶孔；裂缝主要有构造缝、成岩粒缘缝和河道型溶蚀缝。目的层的喉道多数为中喉和粗喉，且沉积物粒度的分选程度较差。根据毛管压力曲线形态，将储层划分为优质储层、中等储层、较差储层和差储层四种储层类型。最后，讨论了储层的储积空间与岩相组合的关系，并认为目的层裂缝发育，但主要发育于半深湖相、泥滩微相、白云岩滩微相、灰质泥滩微相或泥质白云岩滩微相，而生物碎屑滩微相孔隙发育，裂缝相对不发育。

Abstract: This paper deals with the petrological and reservoir properties of carbonate rocks in the lower Shahejie formation of Wangxuzhuang Oilfield. Carbonate rocks mainly include Ostracoda limes-tone, spiralite limestone, gravel limestone, oolitic limestone, micrite limestone and micrite dolo-mite. Pore and fracture are two main types of carbonate reservoir space, which occur in the form of pore-fracture combination. The main pore types are primary intragranular pore, primary intergranular pore, shielding pore, window lattice pore and casting pore, while the main fracture types are structural fracture, diagenetic granular margin fracture and channel corrosion fracture. Most of the throats in the target layer are medium throat and coarse throat, and the sorting degree of sediment granularity is poor. According to the shape of capillary pressure curve, the reservoir can be divided into four types: high quality reservoir, medium reservoir, poor reservoir and poor reservoir. Finally, the relationship between reservoir storage space and lithofacies assemblage is discussed, and it is considered that the fracture of target formation is developed, but mainly in semi-deep lake facies, mudflat microfacies, dolomite beach microfacies, lime mudflat microfacies or muddy dolomite beach microfacies, while the microfacies pore of bioclastic beach is developed and the fracture is relatively undeveloped.